Evaluation of CPI Starch for Laundry Application

By Y. Chen, W. H. Kampen, and B. 1. Collier, Louisiana State University Agricultural Center. Baton Rouge

tarch, as a chemical compound ex- S isting naturally in many agricul- tural products, is not only the major constituent of food but also a natural carbohydrate polymer that is widely used in many industrial section^.^-^ In the laundry industry, starch is used for stiffening clothes for enhanced appear- ance. This is an additional finishing

shirts and jeans following laundering. Commercially, the value of starch products used for the laundering in- dustry relies on their efficiency in stiff-

i I

I b process for many garments such as

ABSTRACT A method to refine corn produces highly pure corn protein isolate (CPI) and intact granular starches (CPI starch). The CPI starch is superior to other commercial starches because of its intact membrane. This paper reports on the effectiveness of the CPI starch in laundering applications by comparison with a commercial starch and polyvinyl alcohol (PVA). Influence of the different starch materials on fabric mechanical properties was examined using the Kawabata Evaluation System for Fabrics (KES-FB) and ASTM and AATCC standard methods. Potential cost savings of using the CPI starch in the laundry industry were assessed. Results indicated that the CPI starch was more effective and economical than the commercial starch as a stiffening agent for the laundry industry with potential savings of at least 33%. Its excellent film forming ability also contributed to dimlnishing impairment of extensibility, compressibility, and surface properties of textiles by starching.

KEY TERMS Corn Protein Isolate CPI Starch Laundry Starch

ening clothes, their ability to produce a good appearance for washed clothes, and their ability to make ironing easier. The laundry industry is presently be- ing challenged to reduce production costs. Thus, applications of a high-ef- ficient starch product will benefit the laundry industry. This paper evaluates the competitiveness of CPI corn starch in laundering applications and com- pares it with commercial starch and PVA. The objectives were to determine the mechanical properties of starched fabric that are influenced by different starch products and polyvinyl alcohol (PVA) and to evaluate primary physi- cal characteristics of the starched fab- ric which are dependent on the liquid properties of different starch products.

New Corn-Refining Process The corn wet-milling industry is con- siderably larger than the corn dry-mill- ing industry and produces the bulk of the starches. In wet milling, the starch is steeped in water to which SO, is added for approximately 48 hours at 120F. This softens the corn kernels and allows the main kernel components as endosperm (mainly starch), germ (oil), bran, and tipcap to be obtained through degermination and classification tech- niques. The ground endosperm is also cooked and as a result the membranes surrounding the starch granules have been ruptured. EnerGenetics Inc. has the rights to a patented process i n which high-lysine or opaque 2 corn is defatted with l i p i d propme, ground very finely in a wet attrition mill, the protein extracted with alkali, and pro- tein and starch separated in a centri- fuge (Westphalia) before further pro- cessing. The protein undergoes microfiltration (Applexion) with inor- ganic membranes and spray drying. The starch is washed in a series of hydroclones and also spray dried. No steeping (SO,) is used and as a result starch granules with intact membranes are obtained, with some special prop- erties. Nondenatured corn protein iso- late (CPI) is also obtained.

Experimental Method

Materials The experimental CPI starch used was a modified product furnished by the Louisiana State University Audubon Sugar Institute. The protein was ex- tracted at high pH values and separated from the starch through centrifugation and hydroclones. A commercial wheat starch, Quix (Textile Care Inc.) was se- lected for comparison purposes. A commercial PVA, Airvol 205s (Air Products and Chemicals Inc.), was also used for starching fabric and yarn. This PVA is a fine particle powder with a 87.0-89.0% hydrolysis range.

The experimental CPI starch, wheat starch, and PVA were used to make 3% solids liquid starch and 3% solids PVA solutions. The concentration repre- sents the typical value used in home and industrial laundering and it can ensure stiffness of the starched fabric within the measurement scale for the lab instruments. Pure starch is in- soluble in water and has no adhesive characteristics. To work as a stiffener, it should be gelatinized to form a paste.4 In this work, the CPI corn starch and wheat starch were first dispersed in distilled water to form a granular slurry, then were heated to the boiling point and held for 10 minutes. The PVA product is cold water-soluble. However, to obtain an optimal solu- tion, it was heated according to the manufacturer’s recommendation. The PVA powder was dispersed in distilled water, and the room-temperature solu- tion was then heated to 185-205F (85- 96C) and held for 30 minutes.

The viscosity of these starch solu- tions was measured using Brookfield Viscometer Model RVT at a liquid tem- perature of 24C. Measured data are listed in Table I, with values for some other commercial starch products.

Sample Preparation and Testing A plain cotton sheeting fabric (177 g/m2) was used for all treatments. Fab- ric samples sized 45 x 70 cm were im-

November 1998 Textile Chemist and Colorist 25

Table 1. Solution Viscosity

Solution Solids (“A) Viscosity (cP)

CPI cornstarch 2 CPI cornstarch 3 Wheat starch 3 Faultless starcha 3 Sta-Flob 7 PVA (Aircol 205s) 3

13 121 37 22 35

8

aCommercial wheat starch mixed with PVA. bcommercial liquid starch for home laundry.

mersed in the starch solutions for 15 minutes and then were padded twice in a padding machine (Birch Brother Inc.). Padded fabric samples were placed in an oven to dry for 15 min- utes. The drying temperature was 1OOC (212F). After drying, the fabric samples were stored under controlled labora- tory conditions (70F, 65% RH) for at least 24 hours before testing. Fabric washing-off was evaluated by compar- ing the mechanical properties of the fabric before and after washing; that is, by measuring how much the mechani- cal properties of the washed starched fabric samples compared to the washed fabric samples without starch.

The starched fabric samples were washed according to AATCC Test Method 61-1994, using a Launder- Ometer.5 The washing temperature was 105F (40C) and washing time was 45 minutes. AATCC standard reference detergent was used for washing (con- centration 0.37%). The moisture-bal- anced fabric samples treated with the 3% CPI starch, 3% wheat starch, and 3% PVA were tested using the Kawabata Evaluation System for Fab- rics (KES-FB).6 Tear strength of the starched fabrics was tested using ASTM Method D2261-83.7 An Instron (model 4301) was used to tear the starched fabric samples and to record tear strength as average peak value and mean value. The liquid starch absor- bency was tested using AATCC Method 79-1992.5 This method mea- sures elapse time when a drop of starch solution visually disappears on the surface of the fabric. In turn, the re- corded time will be used to express how well the siarcli solntioii penetrates into the fabric. Scanning electron mi- croscopy (SEM) was used to observe starch films formed on yarn surfaces and starch penetration into yarn.

Results and Discussion

Mechanical Properties Starch and sizing materials dramati- cally alter the hand and the mechani- cal properties of textile fabrics. The ef- fectiveness of starches on fabric mechanical properties can be evalu- ated by determining fabric mechanical

26 Textile Chemist and Colorist

Before Parametera Starch

LTI WTI RT 1 LT2 WT2 RT2 EMTI EMT2

G1 2HG-1 2HG5-1

2HG-2 2HG5-2

G2

B1 2HB1 82 2HB2

LC wc RC EMC

TO W

MIUI MMDl SMDI MIU2 MMD2 SMD2

0.655 8.35

48.50 0.574

17.65 47.88

5.10 12.30

1.313 3.325 6.100 1.225 3.200 5.350

0.1088 0.1338 0.0763 0.0825

0.285 0.203

36.95 39.31

0.725

0.2140 0.0953

0.2198 0.1008 8.245

177

11.038

Table II. Mechanical Properties of Starched Fabrics

After Starching

3% CPI Starch

0.744 9.30

45.70 0.798

22.95 35.08 5.00

11 5 0

13.250 27.500 35.250 12.125 36.500 44.000

0.7472 0.6804 0.4982 0.5893

0.286 0.192

50.12 39.20

0.71 0 188

0.1715 0.0556 9.040 0.2120 0.0925 7.045

3% Wheat Starch

0.782 8.60

46.51 0.888

26.85 31.10 4.40

12.10

11.500 21.750 34.250 10.750 28.000 42.250

0.7381 0.701 7 0.4617 0.4708

0.284 0.184

49.42 36.48

0.720 189

0.1805 0.0894

0.1 985 0.0963 7.355

10.005

3% PVA

0.909 7.50

47.33 0.936

19.30 38.86

3.30 8.25

10.375 16.000 37.500

7.000 13.500 32.500

0.9082 1.0936 0.4648 0.5620

0.322 0.176

37.12 33.59

0.700

0.1810 0.0763

0.1910 0.1076 8.080

188

10.920

After Washing

3% CPI 3% Wheat . . Starch

0.708 10.00 42.00

26.00 31.15

5.65 13.49

6.000 9.750

23.750 6.375

16.250 30.250

0.771

0.3767 0.4192 0.2066 0.1 944

0.395 0.365

47.12 42.77

0.865

0.1735 0.0898 8.860 0.1670 0.0448 6.770

183

Starch

10.20 43.14

25.25 32.08

5.60 13.10

7.000 12.000 26.25 6.125

14.250 27.750

0.729

0.771

0.4192 0.4617 0.2309 0.2187

0.310 0.221

39.37 36.77

0.775

0.1865 0.0945

0.1835 0.0762 9.015

186

10.670

3% PVA

0.613 9.65

44.56 0.582

22.55 36.81 6.30

15.50

1.500 4.250 7.500 1.500 5.000 8.000

0.1088 0.1763 0.0788 0.0963

0.262 0.213

34.37 41.14

0.790

0.2090 0.1200

0.2440 0.0889 8.855

184

11.580

~~

aLT is Tensile Linearity; WT is Tensile Energy (gf*cm/cm2); RT is Tensile Resilience (“A); EMT is Extension at Tensile Stress 500 gfkm (%); G is Shear Stiffness (gf/cm*degree); 2HG is Shear Hysteresis at 0.5” (gWcm); 2HG5 is Shear Hysteresis at P(gf/cm); B is Bending Rigidity (gf*cmz/cm); 2HB is Bending Hysteresis (gf*cm/ cm); LC is Compressive Linearity; WC is Compressive Energy (gf*cm/cmz); RC is Compressive Resilience (%); EMC is Compressive Strain at 50 gf/cmz (%); To is Fabric Thickness (mm); W is Fabric Weight (g/mZ); MIU is Mean Value of Frictional Coefficient; MMD is Mean Deviation of MIU; SMD is Mean Deviation of Surface Roughness (micron); 1 is Warp Direction; 2 is Filling Direction.

behavior before and after application of the starch. Table II lists all measured KES-FB instrumental data for tensile, shear, bending, compressive, and sur- face properties of fabric samples.

Tensile Properties After starching, fabric tensile linearity and tensile energy (WT) increased, and tensile resilience (RT) and extension (EMT) decreased (Fig. 1). But accord- ing to the paired t-test, the difference in the tensile properties among the CPI- starched, wheat-starched, and PVA- starched fabrics was not significant at the 90% confidence leveLs

Shear Properties Fabric shear stiffness is the primary parameter for evaluating the effective- ness of starch products in stiffening fabrics during laundering. Fig. 2 shows the CPI starch increased fabric stiffness more than either the wheat starch or PVA (significantly greater at the 90% confidence level). This is because the liquid CPI starch can form a thick layer of film on the fabric surface. This film layer greatly restricts fabric shear

movement by cementing warp and fill- ing yarns together. Figs. 3-6 are images, obtained using a scanning electron microscope (SEM), which show the surface of a yarn coated with the CPI starch liquid, wheat starch liquid, and PVA liquid. It can be clearly seen that the CPI starch liquid formed a rela- tively uniform film on the yarn surface. The wheat starch and PVA did not pro- duce a similar film on the yarn surface.

Bending Properties Bending flexibility of the starched fab- rics is evaluated by bending rigidities. The CPI starch can produce higher bending rigidities than the wheat starch (Fig. 7). In comparison with PVA, the fabric sample coated with CPI starch has higher bending stiffness in the filling direction. Furthermore, the CPI starch keeps the lowest bending hysteresis in the fabric warp direction, showing excellent recovery of bending deformation. These measured results indicate that the CPI starch possesses better performance in affecting fabric bending properties than the wheat starch or PVA.

Vol. 30, No. 11

LT1 1.00 T

....... Before Starched

3% Corn Starch

3% Qum Starch

1 LT2

g. 1. Comparison of tensile properties.

Fig. 5. Yarn surface coated with PVA.

81 1.1

....... Before Starched

-3% Corn Starch

-3% Qurt Starch 3% WA _ _ _ _ ~

1 LC

g. 7. Comparison of bending and compression.

November 7998

01 50.0

30.0 t 2HG1

. . Before Starched

-3% Corn Starch

3% Quu Starch

i G2

1. 2. Comparison of shear properties.

Fig. 4. Yarn surface coated with wheat starch.

Fig. 8. Yarn cross section coated with CPI starch.

Textile Chemist and Colorist 27

Fig. 9. Yarn cross section coated with wheat starch. Fig. 10. Yarn cross section coated with PVA.

Fig. 11. Yarn cross section without starch film.

Compressive Properties The measured fabric compressive properties are also shown in Fig. 7. Generally, there are no significant dif- ferences among the CPI starch, wheat starch, and PVA at the 90% confidence level. By comparison with PVA, the CPI starch helps to obtain better com- pressive properties; that is, lower com- pressive linearity, higher compressive energy, and higher compressive resil- ience. In particular, fabric finished with the CPI starch had the highest compressive strain. This was closest to the original value of a fabric sample without starch. The larger the compres- sive strain, the more a fabric can be compressed. Usually, the fabric com- pressibility will be reduced after

MU1 0.25

. . . . . . . Before S t B T C M

3% Corn Starch 3% Quk Staroh

ShlMHM

ig. 12. Comparison of surface properties.

starching. But the CPI starch has an advantage of keeping the fabric com- pressibility close to its original value. This advantage arises from its limited ability to penetrate into fabric yarns. Figs. 8-11 are SEM images showing the cross-section of a yarn in the fabric. In Fig. 8, the CPI starch forms an even layer of coating round the yarn surface and does not penetrate into the fiber bundle, so that the yarn retains its bulk. In Fig. 9, the yarn surface is coated by the wheat starch that has entered the outer layer of the yarn bunch to form a hard surface ring, This surface ring considerably impairs the fabric com- pressibility. It can also be seen from

Fabric

Table 111. Tear Strength of Fabric Before and After Starching (kg)

Average Peak I Mean I Duncan Groupinga Duncan Groupinga

Warp Filling Warp Filling

unstarched 2.839 I A 2.851 I A 1.729 /A 1.698 I A 3% CPI starch 2.402 I B 2.425 I B 1.357 I B 1.500 I B

3% PVA 2.596 I B 2.501 IB 1.470 I C 1.552 I B 3% wheat starch 2.435 I B 2.430 I B 1.386 I BC 1.477 I B

Fig. 10 that the PVA solution pen- etrates well into the yarn bundle to stick fibers together. As a result, the yarn becomes compact and the fabric compressibility is markedly reduced.

Surface Properties The CPI starch decreases fabric surface friction and roughness more signifi- cantly than the wheat starch and PVA, except for the weft frictional coefficient MIU2 (Fig. 12). The measured results indicate that the CPI starch has greater ability to improve fabric surface prop- erties when used as a stiffening agent. This will also help warp yarns obtain abrasion resistance during the warp

Table IV. Shear Stiffness and Bending Flexibilitya

Property ParameteP 2% CPI starch 3% Wheat starch

Shear G I 13.310 2HG-1 31.250 2HG5-1 39.130 G2 12.250 2HG-2 34.500 2HG5-2 43.875

Bending 81 0.701 7 2HB1 0.9751 82 0.3980 2HB2 0.5377

11.500 21.750 34.250 10.750 28.000 42.250

0.7381 0.701 7 0.4617 0.4708

aMeans with the same letter are not significantly different at the confidence level 99%.

T h e paired t-test indicates significant difference at the confidence level 95%. bl is the fabric warp direction; 2 is the fabric filling direction.

28 Textile Chemist and Colorist cco Vol. 30, No. 11

,

82

2 w 2 B1

t 2 w 2 J

G2

Fig. 13. Comparison of fabric stiffness.

Table VI. Recovery Percent of Shear and Bending Stiffness (“A)

Shear Stiffness= Bending Rigidityb Sample Warp Filling Mean Warp Filling Mean 3% CPI starch 61 53 57 58 69 64 3% wheat starch 44 49 46 51 60 55 3% PVA 98 95 97 100 99 100

=Paired t-test indicates significant difference between the CPI starch and PVA at the confidence level 95%. bPaired t-test indicates significant difference among the CPI starch, wheat starch, and PVA at the confidence level 95%.

-

sizing process. This advantage of the CPI starch is derived once again from its special property of forming a uni- form starch film on the surface of the fabric as shown in Fig. 3 . In contrast, the coating films produced by the wheat starch and PVA, as shown in Fig. 4 and 5, are too thin to cover cavi- ties on the yarn surface.

Tear Strength After starching, textile materials tend to be crisp and their tear strength will be reduced. Measured tear strength is listed in Table 111. Multivariate analy- sis of variance indicated that the fabric tear strength decreased significantly after starching. But for the CPI starch, wheat starch, and PVA, there was no significant difference affecting the tear strength except mean tear strength in warp direction.

Potential Savings for Laundry Shear stiffness and bending flexibility of the starched fabrics are the most sig- nificant and important properties to assess starch quality for the laundering industry. By comparing these mechani- cal parameters measured using the KES-FB instruments, potential savings to the laundry industry by using the corn starch product can be estimated. In this research, the solids of the CPI starch solution were reduced from 3% to 2 % . Fabric samples were treated with the 2% CPI starch solution and compared with those fabric samples treated with the 3% wheat starch. Mea- sured results are listed in Table IV and illustrated in Fig. 13. Paired t-test was

Table V. Time for Absorbing Liquid Starch (min)

Solids (“7’0)

Solution 0 1.5 3 6 CPI starch 0.02 27 30a 46 Wheat starch 0.02 11 348 46 PVA 0.02 0.03 0.07 0.24

a30 means 30 minutes to stop absorbing; 34 means 34 minutes to stop absorb- ing. b4 means non-absorbent.

-

~~

Table VII. Weight Loss after Washinga

Fabric Sample Before Wash After Wash Weight Loss (%)

3% CPI Starch 184 183 0.5 3% Quix Starch 186 186 0 PVA (Airvol205S) 187 184 1.6

aWeight unit: g/m2

~

used for testing differences between two means of the KES-FB parameters.

For fabric shear properties, the 2% CPI starch produced greater fabric stiff- ness than the 3% wheat starch at the 95% confidence level. For fabric bend- ing properties, there were no significant differences between the 2% CPI starch and 3% wheat starch. This indicates that users can reduce their amount of starch usage by one third when they re- place wheat starch with the CPI corn starch and still obtain comparable re- sults. This potential savings using the CPI corn starch was confirmed in a test implemented in a local laundry com- pany. Using approximately half the amount of the CPI starch still produced the same stiffening effect as using the regular amount of commercial starch. The CPI corn starch was powdered, so it was as easy to handle as other com- mercial starch powders. In the laundry company, the CPI starch powder was cooked to form liquid starch and then pumped into wash machines before the final wash and chain. There was n o starch buildup on the wash machines. The cooker could be cleaned easily right after cooking.

Physical Properties

Liquid Starch Absorbency Liquid starch absorbency is a measure of the fabric’s ability to absorb starch solutions. The test results are listed in Table V. As shown in Fig. 5, the PVA solution was absorbed by the cotton fabric very quickly because PVA is soluble and its solution has very low

viscosity. In contrast, the cooked CPI starch and wheat starch became a paste which formed a relatively thick coating layer on the fabric. This led to a low penetration of the starch solutions into the fabric. Only the 1.5% solids solu- tions were absorbed by the cotton fab- ric; the 3% solids solutions were par- tially absorbed and the 6% solids solutions were not absorbent.

Washing-Off The ability to wash off starch or PVA materials from clothes or yarns is very important to many end users, particu- larly to fabric manufacturers. During the production of woven fabrics, it is required that starch materials be re- moved (desized) easily from sized yarns in the finishing process to ensure finishing quality of fabrics. The me- chanical properties of starched fabrics after washing are listed in Table 11. For the two most important properties, shear stiffness and bending stiffness, the percent of recovery to their original values is listed in Table VI.

After washing, the mechanical properties of the fabric samples starched with the CPI starch and wheat starch partially recovered compared with their original properties. In con- trast to this, the fabric sample starched with PVA obtained an almost full re- covery to its original properties after washing. This indicates that PVA is much easier to remove from fabric sur- faces by washing and, therefore, has good desizability for warp sizing. The CPI starch and wheat starch were not as easily removed since they remained in the fabric after washing. However, this feature is beneficial for the laundry application. Clothes are usually washed and starched on a daily basis. For those clothes, such as shirts, that need starching during each washing, it is not necessary to require a complete removal of starch materials. Instead.

~.

-

November 7998 a Textile Chemist and Colorist 29

.*

retention of the starch may save on the amount of starch required for daily use. Comparing the CPI starch and wheat starch, there was no significant differ- ence between them in terms of the washing-off property.

How much fabric weight decreases after washing also indicates, to some extent, the ease of removing starch materials from fabrics by washing. Weight changes of the fabrics before and after washing were measured and are listed in Table VII. The weight loss of PVA was 1.6%, significantly larger than those of the CPI starch and wheat starch, with weight losses of 0.5% and zero, respectively.

Conclusions For laundry application, 33% less ex- perimental CPI corn starch achieved results similar to those for the commer- cial wheat starch. This shows that wheat starch users can reduce the amount of starch usage by at least one- third when using this corn starch prod- uct.

The CPI corn starch produced lower surface friction and surface roughness than the wheat starch. This indicates that the CPI corn starch is of a higher quality for laundry use in improving fabric surface properties and modify- ing cloth hand.

The CPI corn starch was similar to the wheat starch in washing-off. After washing, the original mechanical prop- erties of the fabric starched with the

corn starch were partially recovered. This is beneficial for the laundry appli- cation. For starched clothes that un- dergo two or more cycles of washing and starching, the amount of starch used in washing can be reduced be- cause the stiffness of these starched clothes still remains relatively higher than that of unstarched clothes.

Compared with the wheat starch and PVA, the CPI corn starch solution demonstrated a lower ability to pen- etrate fabrics or yarns. The starch film was formed on the fabric and yarn sur- face. This starch film structure led to less impairment of extensibility and compressability of the fabric by starch- ing. For the fabric starched with the wheat starch and PVA, the extensibil- ity and compressability were reduced considerably because of high penetra- tion of the starching solutions into the fabric.

The experimental CPI corn starch had a similar add-on value to PVA. This might encourage further investi- gation of the corn starch for warp siz- ing applications.

There was no significant difference between the CPI corn starch and the wheat starch in affecting fabric tear strength. Average reduction of the tear strength was 15.2% for the corn starch and 14.5% for the wheat starch. For the fabric starched with PVA, the tear strength was reduced by 10.5% on average.

Acknowledgments The authors would like to acknowl- edge their sincere thanks to EnerGen- etics Inc. for sponsoring this project and to Frank Kean and Don McDaniel of Kean’s The Cleaner for their permis- sion and assistance in carrying out the commercial laundry testing.

References 1. Osman, ElizahethM.,Food TheoryandAppli-

cations, edited by Pandline C. Paul and Helen H. Palmer, John Wiley &Sons Inc., New York, N.Y., 1972, p351.

2. Harvey, A,, Laundry Chemistry, 2nd edition revised, The Technical Press Ltd., London, England, 1935.

3. Johnson, J. C., Industrial Starch Technology Recent Development, Noyes Data Corp., Park Ridge, N.J., 1979.

4. Dintzis, Frederick R. and George F. Fanta,Jour- nal of Applied Polymer Science, Vol. 62, No. 5, October 1996, ~ 7 4 9 .

5. AATCC Technical Manual, American Associa- tion of Textile Chemists and Colorists, Re- search Triangle Park, N.C., 1994.

6. Kawahata, S., The Standardization and Ana1,v- sis ofHand Evaluation, 2nd edition, The Tex- tile Machinery Society of Japan, Osaka, Japan, 1980.

7. Annual Book of ASTM Standards Volume 07.02, American Society for Testing and Ma- terials, Philadelphia, Pa., 1994.

8. SAS Institute Inc., SAS /STAT User’s Guide Version 6,4th edition, Vol. 1 and 2, SAS Insti- tute Inc., Cary, N.C., 1990.

Author’s Address Yan Chen, Louisiana State University, School of Human Ecology, Human Ecology Bldg., Baton Rouge, LA 70803- 4300; telephone 225-388-2407; fax 225- 388-2697; e-mail chenyan@unixl.sncc. lsu. edu.

Smoothness Appearance Replicas These replicas are used to visually evaluate the smoothness appearance of fabrics after repeated home laundering. The replicas represent grades of 1 , 2 , 3,3.5,4, and 5. A grade of 5 would represent the smoothest appearance and a grade of 1 would represent the most wrinkled appearance. The replicas are designed for use with MTCC Test Methods 124 and 143. Order No. 8353 .................... ....$345.00

U.S. orders include shipping and handling. Orders outside U.S. must request a proforma invoice.

AATCC P.O. Box 12215, Research Triangle Park, NC 27709

Tel: 91 9-549-81 41 Fax: 919-549-8933 e-mail: ordersQaatcc.org

Visa, Mastercard or American Express Accepted

30 Textile Chemist and Colorist cxx, Vol. 30, No. 7 1